The present invention relates generally to the surveying field and, more particularly, to an apparatus for and method of allowing accurate location and marking of a selected survey point upon the land.
Surveying is the technique of measuring to determine the position of points or of marking out points and boundaries on land. In recent years the utilization of satellite positioning systems, such as the Global Positioning System (GPS) and Global Orbiting Navigational System (GLONASS), have been used to complete surveys. A satellite positioning system comprises a plurality of artificial satellites, radio receivers, computers and other equipment. Satellites transmit signals that indicate their positions relative to the receivers. Computers use these signals to determine the length of measured lines. Specifically, the principal method of using satellites for accurate positioning is based on the application of the Doppler effect. A radio signal is transmitted at a steady frequency by the satellite. A stationary receiving antenna detects a higher frequency as the satellite approaches and a lower one as it recedes. The speed of the frequency change depends upon the distance of the receiver from the satellite""s track. As a consequence, a determination of this speed provides a measure of the distance. Since the track of the satellite over the earth""s surface is known at all times, the data collected defines the position of the receiver. A receiver must obtain signals from at least three satellites to compute latitude and longitude and four satellites to compute elevation.
The use of satellite positioning systems in the field of surveying is described in, for example, U.S. Pat. No. 5,739,785 to Allison et al. and U.S. Pat. No. 5,859,693 to Dunne et al., as well as in the publications xe2x80x9cSite Surveyor: Real Time GPS Survey System,xe2x80x9d Trimble Navigation, October 1992 and xe2x80x9cGPS Satellite Surveying,xe2x80x9d by Alfred Leick, 1990, Wylie-Interscience Publication. The full disclosure of these patents and publications is incorporated herein by reference.
While the broad concept of utilizing satellite positioning systems in the surveying field is well known, further advancements in the application of satellite positioning system technology to the surveying field are desired. Specifically, a far more convenient method of identifying selected survey points and permanently marking these points in the field would allow a survey to be accurately and more efficiently completed in a shorter period of time. Current techniques applying satellite positioning system technology to the surveying field utilize hand-held surveying rover receivers which serve to locate the desired survey marks in conjunction with a base receiver unit for real time GPS surveying. The current methodologies require significant investments in time, labor, and personnel, as the rover receiver(s) must be manually carried to the desired area in order to establish the desired survey point. A system for real-time GPS surveying which eliminated the need for manually carrying and placing the rover receivers, thereby reducing the amount of time, labor, and personnel required to conduct a surveying task, would thus be of great utility.
Accordingly, it is a primary object of the present invention to provide a method and apparatus for surveying overcoming the above described limitations and disadvantages of the prior art.
An additional object of the present invention is to provide a method and apparatus for surveying allowing one to quickly and accurately locate a selected survey point.
Still another object of the present invention is to provide a method and apparatus for reliably and efficiently permanently marking or staking a construction, building or property site accurately at each desired point.
Additional objects, advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects, and in accordance with the purpose of the present invention as described herein, a surveying apparatus for mounting on a wheeled vehicle is provided. The surveying apparatus includes a prism pole, a gyroscope mounted to the prism pole to enable maintaining the prism pole in a vertical orientation to the earth""s surface, a satellite positioning system antenna mounted to the prism pole and a marking device mounted to the prism pole for establishing a survey mark (i.e., building corner or property corner) upon the underlying ground and/or a grade stake for establishing an elevation or grade for a particular point. The surveying apparatus also includes a mounting assembly for securing the prism pole to the wheeled vehicle and an electronic controller.
More specifically describing the invention, the prism pole of the surveying apparatus is secured to the mounting assembly through a gimbal assembly. The gimbal assembly allows the prism pole to be positioned in a vertical orientation in substantially any position of the vehicle with the aid of a gyroscope secured to the prism pole. Additionally, the mounting assembly includes a means for adjusting the position of the prism pole and the gimbal assembly relative to the wheeled vehicle. Preferably, the adjusting means takes the form of a pivot point and a slide which allows substantially infinite fine adjustment within a useful range. As a result, the vehicle needs only to be driven close to the desired survey point and then the adjustment mechanism may be used to efficiently and accurately move and hold the prism pole over the selected survey point.
In the most preferred embodiment, the marker that is mounted to the prism pole is a laser range finder axially mounted adjacent to the lower end of the pole, with a gyroscope secured to the prism pole to allow automatically maintaining a vertical orientation of the prism pole to the earths"" surface. When activated, the laser range finder visually images the survey point on the ground, and sends a signal to the controller to adjust the height of the satellite positioning system antenna above said survey point, thus providing the elevation of that point. Of course, other markers could be utilized including, for example, a laser pointer to mark a point at the desired position upon the ground, or a spray paint device which allows the spray painting of the point at the desired position upon the ground. In many situations this could be accomplished without leaving the vehicle.
In the alternative, the surveying apparatus may be described as comprising a prism pole, a satellite positioning system antenna mounted to the prism pole, a mounting assembly for securing the prism pole to the wheeled vehicle, a gyroscope secured to the prism pole which in combination with a self-orienting connection assembly allows the prism pole to be maintained in a vertical orientation, and an electronic controller. As described above, the self-orienting connection assembly is preferably a gimbal assembly although other structures known to be useful for such a purpose could be utilized.
In accordance with a further aspect of the present invention a method is provided for accurately locating and marking a selected survey point upon land. The method includes the steps of temporarily identifying a selected survey point on the ground, aligning a permanent marker over the temporarily identified selected survey point and securing the permanent marker in the ground at the selected survey point. This method may also be further defined as including a step of locating the selected survey point using a satellite positioning system.
Still further, the method may be described as comprising the steps of using a surveying apparatus for locating a selected survey point, maintaining the surveying apparatus in plumb, providing a temporary visual indication of the selected survey point on the ground, maintaining clearance between the surveying apparatus and the selected survey point temporarily visually indicated upon the ground to allow the actual point to be located with a pin, etc., aligning a permanent marker at the selected survey point and securing the permanent marker in the ground at the selected survey point. Still further, the method may include the step of measuring a distance between the surveying apparatus and the selected survey point temporarily visually indicated upon the ground. Knowing this distance allows one to establish the chosen grade where desired.
Still other objects of the present invention will become apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.